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  • Graphene is cool stuff.

  • The single-atom thick layer of carbon has a number of properties that make it almost

  • endlessly useful.

  • Because of all the neat tricks it can do, it’s popularly dubbed a “wonder material,”

  • but over a decade and a half after it was first isolated, the only thing I’m wondering

  • is: where it is?!

  • Turns out the stuff is really hard to make in useful quantities, but a recent breakthrough

  • from researchers at Rice University promises to make large amounts of graphene in a flash

  • from your trash.

  • For those of you watching your first episode of Seeker ever, (congrats, welcome, hi) graphene

  • looks like this.

  • This is what I call a graph-ic.

  • Anyway, it’s not much to look atit kind of resembles chicken wire.

  • But this honeycomb lattice of carbon can do some amazing things.

  • It is one of the thinnest, strongest, and most conductive materials we have ever discovered.

  • Its strength can be used to make other materials stronger.

  • Its amazing conductivity could help us make energy-dense batteries or efficient heat sinks.

  • Its flexibility could make wearable electronics and bendable displays.

  • You get the ideado I really need to keep going?

  • Which is why it is so frustrating that it’s so hard to make in large amounts.

  • Ironic, considering it was first isolated by applying a piece of sticky tape like you

  • might have in your home to a block of graphite and peeling it off, then resticking and peeling

  • the tape apart until youre left with thin flakes.

  • It’s like it’s taunting us.

  • But there’s a reason we don’t have armies of people just peeling tape apart.

  • The graphene that this technique produces is still a few layers thick, and we're after

  • that single-atom-thick goodness.

  • As of right now, the prevailing methods to achieve that usually involve assembling it

  • on sheets of copper, then using plastics and chemicals to get it off.

  • But the process is slow, expensive and not environmentally friendly.

  • A piece of 60mm x 40 mm monolayer graphene on copper will cost you about $172.

  • But what if were overthinking this?

  • What if we could just take any old carbon source and zap it to make graphene?

  • As far as I can tell, that’s basically the line of thinking the researchers from Rice

  • University followed.

  • The process they developed involves charging up high-voltage capacitors with electricity,

  • then unleashing it all at once into just about any carbon-containing material.

  • Anything from coal, which is basically all carbon to start with, to plastics, to food waste.

  • The current passes through the target material, heating it to over 3,000 Kelvin and breaking

  • every carbon-to-carbon bond in the process.

  • The non-carbon elements sublime out, while the carbon atoms rearrange themselves as graphene.

  • Excess energy is dispersed as light, so researchers dubbed the productflash graphene.”

  • The change can take as little as ten milliseconds.

  • Not only does this produce a gram of graphene quickly and cheaply; it also makes a particular

  • kind of graphene called turbostratic graphene.

  • Unlike A-B stacked graphene, which has orderly layers that are hard to pry apart, the layers

  • of turbostratic graphene have no ordered alignment.

  • This means they can be easily separated using solvents or inside composite materials.

  • Now, this process doesn’t make large sheets of graphene, just small flakes.

  • So it may not be the breakthrough that leads to flexible screens you can put on a T-shirt.

  • But it still has some very usefulalbeit less flashyapplications.

  • The researchers envision flash graphene being added to concrete, and estimate that just

  • a fraction of a percent of graphene added in could boost cement’s strength by 35%.

  • That translates to less building material needed, saving costs and lessening the environmental

  • impact.

  • Flash graphene could be an ecological double win, because it can be made with recycled

  • plastic or food waste, or it could be an alternative use for cheap coal that doesn’t involve

  • burning it and releasing CO2.

  • The Department of Energy thinks turning coal into graphene looks promising, and are funding

  • the research with the goal of producing a kilogram of flash graphene a day within two

  • years.

  • I know were all clamoring for graphene to take the world by storm, but the reality

  • is that itll take incremental steps like this to bring this wonder material into our

  • daily lives.

  • It’s already showing up in places that are hard to spot, like inside headphones and the

  • coating of motorcycle helmets.

  • Now thanks to this new work, it may soon show up in our buildings, too.

  • And the only way you might be able to tell is if you measured the thickness of the walls,

  • or noticed there was suddenly a lot less plastic and banana peels lying around.

  • One of the lead researchers from Rice, James Tour, started experimenting with making graphene

  • out of odd sources because of a bet in 2011 when a colleague challenged him to make it

  • out of, among other things, cockroaches and dog poop.

  • Thanks for watching, if you like this video you can check out more like it, like this

  • one on angled graphene, and subscribe for even more videos.

  • I’ll see you next time on Seeker.

Graphene is cool stuff.

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B1 中級

石墨烯 "神奇材料 "現在可以用TRASH製造了。 (Graphene ‘Wonder Material’ Can Now Be Made Using TRASH)

  • 1 1
    林宜悉 發佈於 2021 年 01 月 14 日
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